Ultrasonic Spray-Coating of Large-Scale TiO2 Compact Layer for Efficient Flexible Perovskite Solar Cells

Optoelectronic Enhancement of Perovskite Solar Cells through the Incorporation of Plasmonic Particles

The optoelectronic advantages of anchoring plasmonic silver and copper particles and non-plasmonic titanium particles onto zinc oxide (ZnO) nanoflower (NF) scaffolds for the fabrication of perovskite solar cells (PSCs) are addressed in this article. The metallic particles were sputter-deposited as a function of sputtering time to vary their size on solution-grown ZnO NFs on which methylammonium lead iodide perovskite was crystallized in a controlled environment. Optical absorption measurements showed impressive improvements in the light-harvesting efficiency (LHE) of the devices using silver nanoparticles and some concentrations of copper, whereas the LHE was relatively lower in devices used titanium than in a control device without any metallic particles. Fully functional PSCs were fabricated using the plasmonic and non-plasmonic metallic film-decorated ZnO NFs. Several fold enhancements in photoconversion efficiency were achieved in the silver-containing devices compared with the control device, which was accompanied by an increase in the photocurrent density, photovoltage, and fill factor. To understand the plasmonic effects in the photoanode, the LHE, photo-current density, photovoltage, photoluminescence, incident photon-to-current conversion efficiency, and electrochemical impedance properties were thoroughly investigated. This research showcases the efficacy of the addition of plasmonic particles onto photo anodes, which leads to improved light scattering, better charge separation, and reduced electron–hole recombination rate.

Light-Stable Methylammonium-Free Inverted Flexible Perovskite Solar Modules on PET Exceeding 10.5% on a 15.7 cm2 Active Area

Perovskite solar modules (PSMs) have been attracting the photovoltaic market, owing to low manufacturing costs and process versatility. The employment of flexible substrates gives the chance to explore new applications and further increase the fabrication throughput. However, the present state-of-the-art of flexible perovskite solar modules (FPSMs) does not show any data on light-soaking stability, revealing that the scientific community is still far from the potential marketing of the product. During this work, we demonstrate, for the first time, an outstanding light stability of FPSMs over 1000 h considering the recovering time (T80 = 730 h), exhibiting a power conversion efficiency (PCE) of 10.51% over a 15.7 cm2 active area obtained with scalable processes by exploiting blade deposition of a transporting layer and a stable double-cation perovskite (cesium and formamidinium, CsFA) absorber.

Dominant effect of the grain size of the MAPbI3 perovskite controlled by the surface roughness of TiO2 on the performance of perovskite solar cells

The surface roughness of the c-TiO₂ layer help controls the perovskite grain size without any other parameter. The direct effect of perovskite grain size on PSC performance is clarified.

An efficient, flexible perovskite solar module exceeding 8% prepared with an ultrafast PbI2 deposition rate

Large-area, pinhole-free CH₃NH₃PbI₃ perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research. The influence of the rate-controlled evaporation of PbI₂ films on the quality of the perovskite layer and the final performance of the planar-structured perovskite solar cells were investigated. An ultrafast evaporation rate of 20 Å s⁻¹ was found to be most beneficial for the conversion of PbI₂ to CH₃NH₃PbI₃ perovskite. Based on this high-quality CH₃NH₃PbI₃ film, a resultant flexible perovskite solar sub-module (active area of 16 cm²) with a power conversion efficiency of more than 8% and a 1.2 cm² flexible perovskite solar cell with a power conversion efficiency of 12.7% were obtained.

Room-Temperature Processing of TiOx Electron Transporting Layer for Perovskite Solar Cells

In order to realize high-throughput roll-to-roll manufacturing of flexible perovskite solar cells, low-temperature processing of all device components must be realized. However, the most commonly used electron transporting layer in high-performance perovskite solar cells is based on TiO₂ thin films processed at high temperature (>450 °C). Here, we demonstrate room temperature solution processing of the TiO_x layer that performs as well as the high temperature TiO₂ layer in perovskite solar cells, as evidenced by a champion solar cell efficiency of 16.3%. Using optical spectroscopy, electrical measurements, and X-ray diffraction, we show that the room-temperature processed TiO_x is amorphous with organic residues, and yet its optical and electrical properties are on par with the high-temperature TiO₂. Flexible perovskite solar cells that employ a room-temperature TiO_x layer with a power conversion efficiency of 14.3% are demonstrated.